Immunotherapy-induced Hepatotoxicity: A Review

Immune checkpoint inhibitors (ICIs) suppress the function of immune checkpoints, which are involved in downregulating immune responses. These lead to an increased activation of the function of T cells, increased release of cytokines, and decreased activity of regulatory T cells. This allows for a more significant and less regulated immune response and subsequent enhanced cytotoxic activity against cancer cells. A number of cancers are now being treated with these agents and this increased use has resulted in more reports of toxicity. While almost every organ can be affected, the skin, gastrointestinal tract, liver, and endocrine glands are most commonly involved. It is necessary that gastroenterologists and hepatologists familiarize themselves with diagnostic steps and management plan in patients with these undesirable outcomes. When assessing for possible ICIs induced hepatotoxicity, it is of utmost importance to use a formal scoring system such as the Roussel Uclaf causality assessment method (RUCAM) to assess for risk factors, alternative causes, and response to cessation and re-exposure of a given drug. While this review is based on studies with and without RUCAM, the conclusions were carefully established mainly from studies that used RUCAM. The aim of this review is to provide information on the epidemiology, risk factors, clinical presentation, diagnostic tools, and management plan based on the most recent studies of immunotherapy-induced hepatotoxicity.